package com.chhuang.mongo.core.servlet;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.chhuang.utils.config.SysConfig;
/**
 * 
 * @author 黄晨
 *
 */
public class CheckCodeServlet extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 4347812572635008371L;

	/**
	 * Constructor of the object.
	 */
	public CheckCodeServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	/**
	 * The doGet method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to get.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		this.doPost(request, response);
	}

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
//		在内存中创建图象   
        int width=100, height=35;   
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);   
//      获取图形上下文   
        Graphics g = image.getGraphics();   
//      生成随机类   
        Random random = new Random();   
//      设定背景色   
        g.setColor(getRandColor(200,250));   
        g.fillRect(0, 0, width, height);   
//      设定字体   
        g.setFont(new Font("Times New Roman",Font.PLAIN,33));   
//      随机产生155条干扰线，使图象中的认证码不易被其它程序探测到   
        g.setColor(getRandColor(160,200));   
        for (int i=0;i<155;i++)   
        {   
         int x = random.nextInt(width);   
         int y = random.nextInt(height);   
                int xl = random.nextInt(12);   
                int yl = random.nextInt(12);   
         g.drawLine(x,y,x+xl,y+yl);   
        }
//      取随机产生的认证码(6位验证码)
        String str="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";   
        StringBuffer code = new StringBuffer();
        for (int i=0;i<4;i++){
        	int k=(int)(Math.random()*36);
        	String c = String.valueOf(str.charAt(k));
        	code.append(c);
            // 将认证码显示到图象中   
            g.setColor(new Color(20+random.nextInt(110),20+random.nextInt(110),20+random.nextInt(110)));   
            //调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成   
            g.drawString(c,20*i+12,28);
        }
//      将认证码存入SESSION
        request.getSession().setAttribute(SysConfig.getValue("checkCode"), code.toString());  
//      图象生效
        g.dispose();
        OutputStream imageOut = response.getOutputStream();
        ImageIO.write(image, "JPEG", imageOut);   
        imageOut.close();
	}
	
	/*   
     * 给定范围获得随机颜色   
     */   
    private Color getRandColor(int fc,int bc){   
        Random random = new Random();   
        if(fc>255) fc=255;   
        if(bc>255) bc=255;   
        int r=fc+random.nextInt(bc-fc);   
        int g=fc+random.nextInt(bc-fc);   
        int b=fc+random.nextInt(bc-fc);   
        return new Color(r,g,b);   
   }

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occurs
	 */
	public void init() throws ServletException {
		// Put your code here
	}

}
